Device for channeling fluid and methods of use

ABSTRACT

Method and apparatus for channeling fluid away from an insertion site having a channel guiding the fluid flow from the insertion site, and a channeling compartment containing absorbent material to wick the fluid such as blood away from the insertion site is provided.

BACKGROUND

Glucose monitoring systems generally include a sensor such as an analytesensor for detecting analyte levels such as glucose levels, atransmitter (such as an RF transmitter) in communication with the sensorand configured to receive the sensor signals and to transmit them to acorresponding receiver unit by for example, using RF data transmissionprotocol. At least a portion of the sensor is inserted through the skinof the patient so as to be in fluid contact with the patient's analyte.The receiver may be operatively coupled to a glucose monitor thatperforms glucose related calculations and data analysis.

The transmitter may be mounted or adhered to the skin of a patient andalso in signal communication with the sensor, at least a portion ofwhich may be inserted in the patient. Generally, the sensor isconfigured to detect and measure the glucose levels of the patient overa predetermined period of time, and the transmitter is configured totransmit the signals related to the analyte (e.g., current signal) overthe predetermined period of time for further analysis. To initially setup the sensor so that the sensor contacts and electrodes are in fluidcontact with the patient's analyte fluids, it is important to properlyinsert the sensor through the patient's skin and securely retain thesensor during the time that the sensor is configured to detect analytelevels.

When the sensor is pierced through the skin of the patient with, forexample, an introducer to properly position the sensor to be in fluidcontact with the patient, the sensor insertion site on the patient'sskin will typically bleed. The amount of blood that would be drawn as aresult of the sensor insertion using the sharp introducer depends atleast upon the insertion site. For example, if the insertion site of thesensor is near capillary vessels or other blood vessels, it is likelythat more blood will be drawn out of the insertion site at the time ofthe sensor insertion process. On the other hand, if the sensor insertionsite is located in an area of the patient's skin that has less capillaryvessels or other blood vessels, it is likely that less blood will resultin response to the piercing process of the skin with the sensorintroducer.

Given that the analyte sensor location will be positioned at theinsertion site, and the likelihood of blood pooling at the insertionsite due to the disturbance of the tissues and the blood vessels by thesharp introducer, it is important to ensure that the drawn-out blooddoes not have significant impact upon the sensor functions including thesensor signals generated by the sensor (for example, using the variouselectrodes of an electrochemical analyte sensor), so that the detectedsignals accurately reflect the patient's analyte level.

In view of the foregoing, it would be desirable to have a method andapparatus which would allow for minimizing the amount of blood poolingat or near the insertion site of the analyte sensor. It would also bedesirable to have a device or method to draw the blood away from theinsertion site of the skin so that it may help facilitate the healingprocess of the skin wound resulting from the piercing of the skin withthe sharp introducer.

SUMMARY OF THE INVENTION

Embodiments of the subject invention include devices that retainbiological fluid at a location distanced from a skin opening, e.g., drawand keep the fluid away from the site. The devices may include asubstrate having one or more fluid-retaining compartments and/orabsorbent material, e.g., positioned within the one or more compartmentsor otherwise. A substrate may be configured to hold an analyte sensortransmitter and/or infusion set cannula in a fixed position on a skinsurface.

In one embodiment, a method and apparatus for channeling fluid away froman insertion site having a channel guiding the fluid flow from theinsertion site, and a channeling compartment containing absorbent orabsorption material to wick the fluid such as blood away from theinsertion site is provided.

More particularly, in accordance with embodiments of the presentinvention, there is provided a device and method for effectively wickingor drawing blood or other fluid away from the sensor insertion site tominimize the potential interference in the sensor-transmitter connectionand thus, providing accurate data associated with the sensor signals,and also, to minimize blood or fluid pooling at or near the sensorinsertion site to provide faster wound healing time and less likelihoodof blood clots, for example.

In addition, within the scope of the present invention, insertion setsof infusion devices such as insulin pumps, may be provided with similarchanneling compartments provided with absorbent material to wick theblood or other fluids away from the insertion site of the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of the fluid channeling device foruse in an analyte monitoring system in accordance with one embodiment ofthe present invention;

FIGS. 2A-2B illustrate a frontal view along the directional arrow A ofFIG. 1 of the fluid channeling device in accordance with respectivealternate embodiments of the present invention;

FIG. 3 is a side view of the fluid channeling device in accordance withone embodiment of the present invention;

FIG. 4 is a bottom view of the fluid channeling device in accordancewith one embodiment of the present invention; and

FIG. 5 is a side view of the fluid channeling device after the insertionof the sensor at the insertion site in accordance with one embodiment ofthe present invention.

DETAILED DESCRIPTION

FIG. 1 illustrates a perspective view of the fluid channeling device foruse in an analyte monitoring system in accordance with one embodiment ofthe present invention. Referring to the Figure, there is provided atransmitter mount unit 100 including a first or base section 101 and asecond or upper section 102 which in this embodiment extendssubstantially transversely to the first section, but which may beotherwise in other embodiments. The transmitter mount unit 100 isconfigured to operatively couple with a transmitter (not shown). Morespecifically, during or after the insertion of a sensor, the transmitteris configured to couple to the sensor at the base section 101 of thetransmitter mount unit 100 such that the transmitter and the sensor arein electrical communication with each other.

As shown in FIG. 1, the transmitter mount unit 100 includes a hollowcavity 104 substantially positioned where the base section 101 and theupper section 102 meet. As will be discussed in further detail below, asensor introducer is operatively coupled with the transmitter mount unit100 substantially at the hollow cavity 104 so as to pierce the skin ofthe patient through the hollow cavity 104 using, for example, a sharpsensor introducer (not shown). Thus, after the sensor insertion process,at least a portion of the sensor is positioned under the skin layer ofthe patient, while the remaining portion of the sensor is positionedthrough the hollow cavity 104 of the transmitter mount unit 100.

Referring again to FIG. 1, also shown is a channel 103 providedsubstantially towards the lower section of the upper section 102 of thetransmitter mount unit 100 such that the hollow cavity 104 on the basesection 101 of the transmitter mount unit 100 and the channel 103 aresubstantially collocated and in fluid connection. In other words, it canbe seen from FIG. 1 that a frontal side 105 of the upper section 102includes thereon the channel 103 so that the channel 103 is alsocontiguous with the hollow cavity 104 of the base section 101 of thetransmitter mount unit 100. In this manner, in one embodiment of thepresent invention, the blood or other fluid drawn onto the surface ofthe skin as a result of the skin piercing with the sensor introducer ischanneled or guided into the channel 103 of the upper section 102 of thetransmitter mount unit 100. As such, there is less blood or fluidremaining at the skin surface around the hollow cavity 104 area wherethe sensor is configured to maintain electrical communication with thetransmitter.

While glucose is described as examples of analytes that is detected bythe sensor in the monitoring system, within the scope of the presentinvention, additional analytes that may be monitored or detectedinclude, for example, acetyl choline, amylase, bilirubin, cholesterol,chorionic gonadotropin, creatine kinase (e.g., CK-MB), creatine, DNA,fructosamine, glucose, glutamine, growth hormones, hormones, ketones,lactate, peroxide, prostate-specific antigen, prothrombin, RNA, thyroidstimulating hormone, and troponin. The concentration of drugs, such as,for example, antibiotics (e.g., gentamicin, vancomycin, and the like),digitoxin, digoxin, drugs of abuse, theophylline, and warfarin, may alsobe monitored.

FIGS. 2A-2B illustrate a frontal view along the directional arrow A ofFIG. 1 of the fluid channeling device in accordance with respectivealternate embodiments of the present invention. Referring to FIG. 2A,the upper section 102 of the transmitter mount unit 100 includes aplurality of channeling compartments 201, each of which is in fluidconnection with the channel 103. Each compartment may have its ownchannel or two or more may share a common channel. More specifically,the upper section 102 of the transmitter mount unit 100 in oneembodiment of the present invention includes five discrete channelingcompartments 201, each of which is configured to house or contain anabsorbent material. In this manner, when blood or other fluid ischanneled into the channel 103 of the transmitter mount unit 100, theabsorbent material contained within the channeling compartments 201 drawthe blood or fluid therein and thus away from the sensor insertion siteon the skin of the patient.

Within the scope of the present invention, the transmitter mount unit100 may be configured with more or less than five channelingcompartments 201. Indeed, the transmitter mount unit 100 may comprise ofa single channeling compartment 201 provided with the absorbentmaterial. Some considerations regarding the number of the channelingcompartments 201 include, but are not limited to, the ease and/or costof manufacturing as well as design considerations.

Referring now to FIG. 2B, in contrast to the embodiment shown in FIG.2A, there is provided one substantially larger channeling compartment202 which is configured to be in fluid contact with the channel 103 ofthe transmitter mount unit 100. As shown in FIG. 2B, the channelingcompartment 202 is configured to house or retain the absorbent materialsimilar to the embodiment shown in FIG. 2A such that the blood or otherfluid that is channeled into the channel 103 will be drawn into thechanneling compartment 202 by the absorbent material when in fluidcontact with the blood or other types of fluid.

FIGS. 3 and 4 are side and bottom views respectively, of the fluidchanneling device in accordance with one embodiment of the presentinvention. Referring to FIGS. 3-4, it can be seen that the inner spaceof the channeling compartment 201 (FIG. 2A), 202 (FIG. 2B) may beloosely filled with absorbent material 301 so that there is sufficientspace to hold the biological fluid, (blood, interstitial fluid, or thelike) and to facilitate the wicking process (or drawing the fluid intothe inner space of the channeling compartment 201 (FIG. 2A), 202 (FIG.2B). Within the scope of the present invention, the absorbent material301 may be placed within the channel compartment 201, 202 so as to notcompletely fill the compartments 201, 202. Such configuration may bedesirable when it is anticipated that the expected amount of blood orother fluids is relatively less, and further, to reduce the cost ofmanufacture. Moreover, by not completely filling the compartments 201,202 with the absorbent material 301, there is provided sufficient roomto absorb blood or other fluid at or around the insertion site.

FIG. 5 is a side view of the fluid channeling device after the insertionof the sensor at the insertion site in accordance with one embodiment ofthe present invention. Referring to FIG. 5, it can be seen that theintroducer 501, which contains at least a portion of the sensor 502 in apre-deployed state within the sharp needle portion of the introducer,upon withdrawal from the insertion site 504 of the skin, draws blood orother fluids through the insertion site 504 onto the skin of thepatient. FIG. 5 further illustrates the deployed and subcutaneously (orotherwise) placed portion of the sensor 502 in the patient at theinsertion site 504.

Referring to FIG. 5, the absorbent material 301 is thus contacted withthe blood or other fluids 503 that are drawn onto the surface of thepatient's skin at the insertion site 504, and draws in the blood orother fluids 503 into the channeling compartment 202 so as to displacethe blood or other fluids away from the insertion site 504.

It has been observed that patients typically bleed less than 10 μL ofblood during the sensor insertion process. As such, the channelingcompartments 201, 202 as shown above in accordance with variousembodiments of the present invention having absorbent material containedtherein, effectively draws or wicks the blood away from the insertionsite, thus minimizing potential interference with the sensorfunctionality and the sensor communication or electrical contacts withthe transmitter. The absorbent material may be able to absorb some orall of the biological fluid at the sensor insertion site, e.g., may beconfigured to absorb as much as about 10 μL (or more in certainembodiments) of fluid.

In accordance with the various embodiments of the present invention, theabsorbent material 301 may include sponge like material, super absorbentmaterials such as polyacylites, for example, and any other suitableabsorbent material such as, but not limited to, polyester, nylon,cellulose, and cellulose derivatives such as nitrocellulose. Theabsorbent material may include an anti-bacterial agent and/oranti-fungal agent. In certain embodiments, the transmitter mount may bemaintained in position on the skin of a subject for one or more days,e.g., one or more weeks, even one or more months in certain instances.The inclusion of an agent may be useful to retard or inhibit the growthof harmful organisms that may be the source of infection, especially inthe event the transmitter is used for a prolonged period of time.

In the manner described above, in accordance with the variousembodiments of the present invention, there is provided devices andmethods for effectively wicking or drawing blood, interstitial fluid orother fluid away from the sensor insertion site to minimize thepotential interference in the sensor-transmitter connection and thus,providing accurate data associated with the sensor signals, and also, tominimize blood or fluid pooling at or near the sensor insertion site topotentially provide faster wound healing time and less likelihood ofblood clots, for example. In addition, users or patients will likelyprefer to draw blood or other fluid away from the sensor insertion siteso as to have a clean or biological fluid-free area substantiallysurrounding the sensor insertion site on their skin.

In addition, within the scope of the present invention, insertion setsof infusion devices such as insulin pumps, may be provided with similarchanneling compartments provided with absorbent material to wick theblood or other fluids away from the insertion site of the patient.

Indeed, in accordance with one embodiment of the present invention,there is provided an apparatus including a housing having a base portionand a side portion, the side portion including at least one compartment,the base portion including an opening positioned to substantiallysurround an insertion site on the skin of a patient, the compartmentconfigured to draw a fluid substantially from around the insertion site.

The apparatus further includes in one embodiment an absorbent materialpositioned substantially within the compartment, where the absorbentmaterial draws the fluid from away the insertion site.

In one aspect of the present invention, the absorbent material includesone or more of polyester, nylon, cellulose, cellulose derivative,nitrocellulose, an anti-bacterial agent or anti-fungal agent.

Further, the absorbent material may be in fluid contact with the fluidsubstantially surrounding the insertion site, so as to draw the fluidaway from the insertion site.

Moreover, in a further embodiment, a portion of a sensor is providedunder the skin of the patient at the insertion site, where the insertionsite substantially corresponds to the transcutaneous position of thesensor on the skin.

The sensor in one embodiment is an electrochemical sensor, and inparticular, a glucose sensor.

Moreover, at least the portion of the sensor may be in fluid contactwith biological fluid of the patient.

In one embodiment, a transcutaneously positioned cannula of an infusiondevice may be provided, where the insertion site of the cannulasubstantially corresponds to the transcutaneous position of the sensoron the skin. In an alternate embodiment, the infusion device may bewholly implantable.

The infusion device in one embodiment includes an insulin pump. Anapparatus in a further embodiment of the present invention includes ahousing comprising a compartment, the housing including an openingpositioned to substantially surround an insertion site on the skin of apatient, an absorbent material provided substantially within thecompartment.

Moreover, the apparatus may further include a sensor with at least aportion of the sensor provided under the skin of the patient, theinsertion site substantially corresponding to a transcutaneous locationof the sensor on the skin.

A method in a further embodiment of the present invention includes thesteps of positioning at least a portion of an analyte sensor, a cannula,or both an analyte sensor and a cannula, at an insertion site on theskin of a patient, and drawing a fluid substantially away from theinsertion site of the patient.

The method in one embodiment may further include the step of contactingan absorbent material with the fluid to draw the fluid substantiallyaway from the insertion site.

The fluid may be one or more of an interstitial fluid or blood.

An apparatus in still a further embodiment includes an analyte sensor,and a substrate for retaining a transmitter in electrical contact withthe analyte sensor, the substrate comprising at least one compartmentfor retaining biological fluid.

The at least one compartment comprises absorbent material, and further,where the at least one compartment comprises an agent to at leastinhibit growth of harmful organisms.

In a further embodiment, the substrate may comprise a first section anda second section, the second section further including the at least onecompartment, where the second section may be substantially transverse tothe first section.

Further, the substrate may be attachable to the skin of a subject instill another embodiment.

A system in accordance with yet still another embodiment includes ahousing comprising a compartment, the housing including an openingpositioned to substantially surround an insertion site on the skin of apatient, an absorbent material provided substantially within thecompartment, a sensor substantially located at the insertion site, and atransmitter unit coupled to the housing, and electrically coupled to thesensor.

An insertion kit in accordance with yet still a further embodimentincludes a housing comprising a compartment, the housing including anopening positioned to substantially surround an insertion site on theskin of a patient, an absorbent material provided substantially withinthe compartment, a sensor, and an introducer coupled to the sensorconfigured to place the sensor at the insertion site on the skin of thepatient so that at least a portion of the sensor is placed under thepatient's skin.

Various other modifications and alterations in the structure and methodof operation of this invention will be apparent to those skilled in theart without departing from the scope and spirit of the invention.Although the invention has been described in connection with specificpreferred embodiments, it should be understood that the invention asclaimed should not be unduly limited to such specific embodiments. It isintended that the following claims define the scope of the presentinvention and that structures and methods within the scope of theseclaims and their equivalents be covered thereby.

What is claimed is:
 1. An apparatus, comprising: a housing comprising atleast one compartment, and including an opening positioned tosubstantially surround an insertion site on a skin surface and toaccommodate a sensor coupled to a sensor introducer for inserting thesensor under the skin surface, wherein at least a portion of the sensoris adapted to be placed under the skin surface at the insertion site,the at least one compartment configured to draw a fluid substantiallyfrom around the insertion site and away from the sensor after theintroducer has inserted at least the portion of the sensor under theskin surface and the introducer has been removed from the insertionsite.
 2. The apparatus of claim 1, further including an absorbentmaterial positioned substantially within the at least one compartment.3. The apparatus of claim 2, wherein the absorbent material draws thefluid away from the insertion site and away from the sensor.
 4. Theapparatus of claim 2, wherein the absorbent material includes one ormore of polyester, nylon, cellulose, cellulose derivative,nitrocellulose, an anti-bacterial agent, or an anti-fungal agent.
 5. Theapparatus of claim 2, wherein the absorbent material is in fluid contactwith the fluid substantially surrounding the insertion site, so as todraw the fluid away from the insertion site and away from the sensor. 6.The apparatus of claim 1, wherein the sensor is an electrochemicalsensor.
 7. The apparatus of claim 1, wherein the sensor is a glucosesensor.
 8. The apparatus of claim 1, wherein the at least a portion ofthe sensor is in fluid contact with biological fluid under the skinsurface.
 9. The apparatus of claim 1, further including a cannula of aninfusion device provided at a cannula insertion site, the insertion siteof the cannula substantially corresponding to the insertion site of thesensor on the skin surface.
 10. The apparatus of claim 9, wherein theinfusion device includes an insulin pump.
 11. The apparatus of claim 1,wherein the housing comprises a plurality of compartments.
 12. Theapparatus of claim 1, wherein the at least one compartment is positionedlaterally from the opening and the insertion site.
 13. A system,comprising: a housing comprising a compartment, the housing adapted tobe maintained in position on a skin surface for one or more days andincluding an opening positioned to substantially surround an insertionsite on the skin surface; a sensor with at least a portion of the sensoradapted to be placed under the skin surface, the insertion sitesubstantially corresponding to a transcutaneous location of the sensoron the skin surface; and an absorbent material provided substantiallywithin the compartment and configured to draw fluid away from thesensor, across the opening and into the housing.
 14. The system of claim13, wherein the absorbent material includes one of polyester, nylon,cellulose, cellulose derivative, nitrocellulose, an anti-bacterialagent, or an anti-fungal agent.
 15. The system of claim 13, wherein thesensor includes an electrochemical sensor, and a first end of the sensoris adapted to be placed in fluid contact with an interstitial fluidunder the skin surface.
 16. The system of claim 13, further including acannula of an infusion device provided at a cannula insertion site, thecannula insertion site substantially corresponding to the insertion siteof the sensor on the skin surface.
 17. The system of claim 13, whereinthe housing comprises a lower section configured for positioning on theskin surface and an upper section extending substantially transverse toand laterally from the lower section.
 18. The system of claim 17,wherein the opening is located within the lower section and thecompartment is located within the upper section.
 19. A method,comprising: positioning a housing including a compartment on a skinsurface, the housing adapted to be maintained on the skin surface forone or more days, wherein the housing further includes an openingpositioned to substantially surround an insertion site on the skinsurface; positioning at least a portion of an analyte sensor, a cannulaor both an analyte sensor and a cannula under the skin surface at theinsertion site; removing one or more introducers used for positioningthe portion of the analyte sensor, the cannula or both the analytesensor and the cannula under the skin surface from the insertion site;and drawing a fluid substantially away from the sensor and from theinsertion site of the patient skin surface using an absorbent materialprovided substantially within the compartment of the housing to alocation inside the housing after the removal of the one or moreintroducers from the insertion site.
 20. The method of claim 19, furtherincluding contacting the absorbent material with the fluid to draw thefluid substantially away from the insertion site.
 21. The method ofclaim 19, wherein the absorbent material includes one or more ofpolyester, nylon, cellulose, cellulose derivative, nitrocellulose, ananti-bacterial agent, or an anti-fungal agent.
 22. The method of claim19, wherein the fluid is one or more of interstitial fluid or blood. 23.The method of claim 19, wherein the location inside the housing islaterally positioned with respect to the insertion site.
 24. The methodof claim 19, wherein the housing comprises a base portion configured forpositioning on the skin surface and a lateral portion extendingsubstantially transverse to and at a side edge of the base portion. 25.An apparatus, comprising: an analyte sensor; a base for retaining atransmitter in electrical contact with the analyte sensor when at leasta portion of the analyte sensor is placed under a skin surface and asensor introducer is removed from the skin surface, the basepositionable entirely above the skin surface; and at least onecompartment for retaining biological fluid away from the analyte sensor,the at least one compartment positioned at a periphery of the base. 26.The apparatus of claim 25, wherein the at least one compartmentcomprises an absorbent material.
 27. The apparatus of claim 25, whereinthe at least one compartment comprises an agent to at least inhibitgrowth of harmful organisms.
 28. The apparatus of claim 25, wherein thebase includes a first section and a second section, the second sectionincluding the at least one compartment, and further, wherein the secondsection is substantially transverse to the first section.
 29. Theapparatus of claim 25, wherein the base is attachable to the skinsurface.
 30. A system, comprising: a housing wholly positionable on askin surface, the housing comprising an opening positioned tosubstantially surround an insertion site on the skin surface andcomprising at least one fluid channel entirely within the housing; asensor substantially located at the insertion site, wherein the at leastone channel is configured to wick fluid away from the sensor; anintroducer coupled to the sensor configured to place the sensor at theinsertion site so that at least a portion of the sensor is placed underthe skin surface upon removal of the introducer from the insertion site;and a transmitter unit coupled to the housing and electrically coupledto the sensor.
 31. The system of claim 30, wherein the at least onechannel comprises a notch in the housing.
 32. The system of claim 30,wherein the at least one channel is in fluid communication with at leastone fluid compartment within the housing.
 33. The system of claim 32,wherein the housing comprises a base portion configured for positioningon the skin surface and a lateral portion extending substantiallytransverse to and at a side edge of the base portion.
 34. The system ofclaim 33, wherein the at least one channel and the at least onecompartment are located within the lateral portion of the housing.